multithreading - java.lang.OutOfMemory Exception with Multithreaded Image Generate -

i trying copy lot of images java imageio. each copy resizes original picture. size of image set huge (60,000). try use multi thread solve problem. here code:

package generate.image  import scala.util.random._ import scala.math._ import java.io.file import java.io.printwriter import java.util.concurrent.{executorservice, timeunit, executors} import java.awt.image import java.awt.image.bufferedimage import javax.imageio.imageio  class imageresizer{     def resizeimage(srcimgpath: string, distimgpath: string, width: int, height: int){         val srcfile: file = new file(srcimgpath)         val srcimg: image = imageio.read(srcfile)         val buffimg: bufferedimage = new bufferedimage(width, height, bufferedimage.type_int_rgb)          buffimg.getgraphics().drawimage(                 srcimg.getscaledinstance(width, height, image.scale_smooth), 0,                 0, null             )         imageio.write(buffimg, "jpeg", new file(distimgpath))     } }  class imageworker(imgsrc: string, imgname: string, width: int, height: int) extends runnable{     override def run(): unit = {         val resizer = new imageresizer()         resizer.resizeimage(imgsrc, imgname, width, height);     } }  object imagegenerate {      def main(args:array[string]): unit = {         // parameters         val dirname = args(0)         val images = new file(dirname).listfiles.filter(_.getname.endswith(".jpeg"))         val imgcnt = images.length           // threadpool         val pool = executors.newfixedthreadpool(25)           // copy norm         for(i <- 0 until imgcnt){             for(cnt <- 1 20){                 val width = nextint(200) + 300                 val height = nextint(200) + 300                 val imgsrc: string = images(i).getabsolutepath                 val imgname: string = "img/%s_%d_%d_%d.jpeg".format(splitfilename(images(i).getname), width, height, cnt)                 pool.execute(new imageworker(imgsrc, imgname, width, height))             }         }           pool.shutdown()         pool.awaittermination(long.maxvalue, timeunit.nanoseconds)     }      // split file name     def splitfilename(filename: string) = {         filename.substring(0, filename.lastindexof("."))     }  } 

imageresizer copy work. reads image bufferedimage, resizes new bufferedimage, , writes jpeg file.

imageworker thread work. executed worker threads in executeservive.

imagegenerate dispatching work. reads image files in args(0) (first arg), generates new random width , height, , submit new job pool.

compile , run: scalac imagegenerate.scala scala generate.image.imagegenerate test. sizes of images 150kb in average.

as running, program throws java.lang.outofmemoryerror. sometimes, there exception in thread "pool-1-thread-36" java.lang.outofmemoryerror: gc overhead limit exceeded error.

if set parameter -j-xmx2048m, program run smoothly. however, run 400 images. there optimization code?

thanks sharing idea, best wishes.

you should calling dispose()

something (untested)

  val graphics = buffimg.getgraphics()   graphics.drawimage(     srcimg.getscaledinstance(width, height, image.scale_smooth), 0,     0, null   )   imageio.write(buffimg, "jpeg", new file(distimgpath))   graphics.dispose()